Apparatus for injecting and withdrawing fluids from a well



Aug. 13, 1968 T. w. LITTLE ETAL 3,396,797

APPARATUS FOR INJECTING AND WITHDRAWING FLUIDS FROM A WELL Filed March 2l, 1966 2 Sheets-Sheet l I T T ...|51 ...li TT T WTTIITVT-nllrlrnfll, IUTHTT., T T. .TT T .TT I aooooa 0000000000 /.f7.1

NVENTORS T. W. LITTLEI By R.E. FINKEN 2 ATTORNEYS 2 Sheets-Sheet 2 /NVENTORS T W. LITTLE By R. E. FINKEN A r ron/vers Aug. 13, 1968 1'. w. LITTLE ETAL.

APPARATUS FOR INJECTING AND WITHDRAWING FLUIDS FROM A WELL Filed March 2l, 1966 FIG. 2

United States Patent C) 3,396,797 APPARATUS FOR INJECTING AND WITH- DRAWING FLUIDS FROM A WELL Thomas W. Little, Fort Worth, Tex., and Robert E.

Finken, Alexandria, United Arab Republic, as-

signors to Phillips Petroleum Company, a corporation of Delaware Filed Mar. 21, 1966, Ser. No. 536,065 7 Claims. (Cl. 166-105) ABSTRACT OF THE DISCLOSURE Apparatus is provided for alternately injecting iluids thru a well into a stratum, such as an oil stratum, and producing fluids thru the well, comprising an elongated tube -attachable at its upper end section to a downhole tubing string below a pump thereon and open on the lo-wer end; valve means, such as a check valve or sleeve valve, in an intermediate section of the tube operable to allow ingress of fluids directly from outside of the tube when in one position and to prevent egress of fluids when in another position; and ra tail pipe on the lower end of the tube communicating therewith for passing injected fluids to a lower level in the well. The apparatus is attached to the lower end of a tubing string containing a retractable pump, there being an expanded section of tubing above the pump into which the pump is drawn to lallow injected fluid to pass around the pump and thru the apparatus into the surrounding stratum.

This invention relates to apparatus for injecting fluids into `a producing stratum around a well therein and producing fluids from the well lby downhole pumping and again reverting to fluid injection without pulling the pump from the well.

Oil is produced from certain types of oil-bearing strata thru a single well penetrating the selected stratum by injecting steam or other heating or viscosity-reducing fluid thru the well into the stratum for a substantial period of time whereby stratum pressure is increased, and after a substantial soaking period, the well is opened to allow stratum pressure to force oil into the Well. The heating, soaking, and production steps are repeated in sequence until it no longer is economic to continue the operation.

In order to avoid pulling the `downhole pump after each pumping step or phase of the process to allow injection of steam or other heating fluid into the stratum, an expanded or enlarged section of tubing has been provided in the tubing string just above the pump so that the pump can be pulled one rod joint upwardly into this expanded section of tubing to permit the injected fluid to bypass t-he pump. This apparatus and technique of operation are disclosed and claimed in the copending application of W. B. Belknap, S.N. 350,254, tiled Mar. 9, 1964.

In field application of the invention of the aforesaid application, the oil sand was relatively thick and a slotted liner was positioned downhole, the upper end being packed off with the surrounding casing. Because of the restricted diameter of the liner, the pump could not be positioned within the liner and was set just above the level of the liner. It was found that when steam was injected it preferentially passed into the upper level of the sand, whereas it was desirable to inject at least as much steam into lthe lower and intermediate sand levels as into the uppermost level.

The invention is concerned with an varrangement of apparatus which permits injection of steam or other oilproducing iiuid thru a tubing string to the lowermost level of -a producing well and pumping thru the same tubing string from an upper level yas well as from lower levels in the well.

Accordingly, it is an objec-t ofthe invention to provide an arrangement of apparatus for injecting oil-producing fluid to the lowermost level of a stratum thru a well penetrating same thru a tubing string provided with a downhole pump positioned above the stratum and pumping from the well thru the same string in normal manner during the production phase of the process. Another object is to provide an arrangement of apparatus which permits downhole pumping at the pump intake level and injection of oil-producing fluid thru the same tubing string in which the pump is located and to a substantially lower level than the pump intake. Other objects of the invention will become apparent to one skilled in the art upon consideration of the accompanying disclosure.

A broad aspect of the invention comprises an elongated tube attachable at its upper end to a downhole tubing string below a pump thereon and open adjacent its lower end; valve means in a section of the tube at an intermediate level therein operable to allow ingress of fluids directly from outside of the tube when in one position and to prevent egress of fluids when in another position; and an elongated section of pipe connected with the lower end of the tube communicating therewith for passing injected fluids to a lower level in the well below the pump intake. In one embodiment of the invention, a -ball check valve permitting flow only into the lower end of the tubing string is positioned below the pump at the end of the tubing string and an arcuate pipe communicating with the lower end of the tubing string intermediate the check valve and the pump thru an opening in the side of the tubing, extending to a point substantially below the lower end of the tubing and in-axial alignment therewith is provided. In this embodiment, the injected steam or other fluid cannot pass thru the check valve and is forced to t-he lower end of the arcuate pipe from which the injected fluid readily passes to the lower sections of the stratum rst and then upwardly to the upper levels of the stratum.

Another embodiment of the invention utilizes a slidable sleeve having ports therein which match or cooperate with similar ports in the wall of the surrounding tubing. The sleeve is removably attached to the lower end of the pump or to an extension of the lower end of the pump so that the sleeve seats in position for flow thru the ports of the sleeve and of the wall of the tubing when the pump is in downhole pumping position and, when the pump is raised into the expanded tubing section, the sleeve is pulled upwardly and positioned with the ports therein out of yalignment with the corresponding ports in the wall of the tubing. It is also feasible to utilize the inside wall of the tubing as the pump barrel with the pump plunger, including the standing valve and traveling valve, pulling upwardly into the expanded tubing section, the sleeve being operated by a downward extension from the pump plunger in similar manner to the arrangement shown hereinafter for operating the sleeve from the lower end of the pump.

A more complete understanding of the invention may be had by reference to the accompanying schematic drawing of which FIGURE 1 is an elevation in partial section thru a downhole arrangement of apparatus illustrating a preferred embodiment of the invention; FIG- URES 2 and 3 are similar views illustrating another ernbodiment of the invention; and FIGURE 4 is an elevation in partial section of a well penetrating a producing stratum.

Referring to FIGURE l, stratum 10` is penetrated by well 12 which is provided with a casing 14 perforated Within stratum 10 as shown at 16. A tubing string 18 extends from a level just above the stratum thru the well-head and is provided with a pump (not shown in this figure but shown in the remaining figures) which seats on a seat provided therefor (but not shown) in the tubing string near the lower end thereof. A sucker rod operates the pump in conventional manner. A liner 20, containing perforations 21, is positioned within the stratum and packed off by packers 22 with casing 14. The annulus between liner 20 and casing 14 Contains a gravel pack 23.

Arcuate pipe 24 connects with an opening 26 in the wall of tubing 18 and extends into a short section of tubing 28 with which it is sealed at the upper end so as to force steam out the lower end of section 28. A brace 30 in the form of a rod or bar is welded or otherwise attached to the lower end of tubing string 18 and to the upper end of section 28 to provide stability for the combination of tubing 18, arcuate pipe 24, and tubing section 28. The section of tubing 28 may be omitted, if desired, and pipe 24 will provide the lower terminus of the combination.

A ball check valve 32 in the lower end of tubing 18 provides for ingress of oil and produced uids on their way to the pump intake but it prevents egress of uids from the lower end of the tubing string into the surrounding area. Thus, when fluid such as steam is being injected thru the tubing string 18, it is forced to ow thru opening or port 26 into pipe 24 from which it flows into tubing section 28 and out the lower end thereof, passing thru the perforations 21 in :liner 20 and thence thru perforations 16 in casing 12 into the surrounding stratum. Hence, FIGURE l illustrates the steam injection phase of the process and the position of check valve 32 for this operation.

Referring to FIGURES 2 and 3, corresponding parts or elements are correspondingly numbered to those in 'FIGURE l. These figures diier from FIGURE l principally in the valve means for allowing ingress of fluids from the well surrounding the tubing and preventing egress of iiuids during steam or other iiuid injection thru the tubing string. Thus, a sleeve valve arrangement is provided comprising sleeve 32 which is provided with a series of ports 34 circumferentially arranged which align with matching ports 36 in tubing 18 in one position of the sleeve, as shown in FIGURE 2, and are in disalignment therewith in another position of the sleeve, as illustrated in FIGURE 3. Sleeve 32 seats on shoulder 38 in the open position to tlow of fluids thru ports 34 and 36 and pump 42 seats on seat 45.

The operation of sleeve 32 is effected by an arrangement comprising section 40 on the lower end of pump 42, a snap ring 44 encircling section 40, and a snap ring 46 encircling sleeve 32A When sleeve 32 is in the open position, snap ring 46 is squeezed into its corresponding groove so that it slidably engages the inner wall of tubing 18 and, as the sleeve is raised into the closed position as shown in FIGURE 3, snap ring 46 expands into groove or seat 48 to lock the sleeve in this position. The upper edge of snap ring 46 is square at the outer periphery thereof and tapered or chamfered along the lower edge so that it cannot be moved out of the groove 48 upwardly but is readily moved downwardly out of the groove by application of sufiicient downward pressure thereon. Cooperating with snap ring 46, snap ring 44 is chamfered or beveled on both outer circumferential edges so that this ring readily enters sleeve 32 and slips into groove or seat 50 on the downward movement of the pump 42 to force the slip ring 46 out of groove 48 and position the sleeve on its seating shoulder 38 and pump 42 on seat 45. Also, on the upward travel of pump 42, snap ring 44 is forced out of seat 50 when sleeve 32 is locked in the closed position by snap ring 46 as it enters groove or seat 48 and the pump continues its upward movement into enlarged tubing section S8 (shown in FIGURE 4).

Referring to FIGURE 4, well 12 penetrates stratum 10,

and tubing string 18 and sucker rod 52 extend from pump 42 thru the wellhead 54. Usually, the annulus between tubing 18 and casing 14 is packed off near stratum 10 above pump level, as by packers 56, to prevent ow of steam upwardly into other strata which may be permeable and to contain fluids downhole. An enlarged or expanded tubing section or joint 58 is provided just above pump 42 so that the pump may be pulled into this tubing section for injection of steam or other fluid around the pump without pulling the pump from the well.

In operation with the arrangement shown in FIGURES l and 4, steam injection is effected by pulling the sucker rod 52 up one joint in conventional manner so that pump 42 (attached to the sucker rod) is positioned in expanded tubing section 58 to permit liow of steam thru the annulus between pump 4Z and the inner wall of tubing section 58. The injected steam iiows readily thru the tubing below section 58 and thru pipe 22 into the lowermost section of the well for passage into the surrounding stratum. During this steam injection ball check valve 32 prevents egress of steam from the lower end of the tubing string except thru passageway 26 leading into pipe 24. After a substantial period of steam injection, which may last several weeks or longer, well 12 is shut in for a substantial soaking period, which may also last several weeks or more, after which tlie well is opened to flow to reduce the pressure downhole and permit flow of oil and condensate into the well. The pump 42 is then lowered onto its seat 45 and the pumping phase of the operation is commenced with oil passing into the pump intake thru ball check valve 32 and/or pipe 24, both passageways being open to upward liow of fluid.

A similar procedure is followed when operating with the sleeve valve arrangement of FIGURES 2 and 3, sleeve 32 being in open position relative to ports 34 and 36 during the pumping phase of the operation (illustrated in FIGURE 2) and closed to flow during the steaming phase of the operation, as illustrated in FIGURE 3 and explained hereinbefore.

It can readily be seen that the valve arrangement of either FIGURE 1 or of FIGURES 2 and 3 permits normal pumping of well fluids but forces injected uids completely to the bottom of the stratum which is being produced. Tail pipe 24 or its counterpart in FIGURES 2 and 3 may extend from l0 to 50 feet or more below the upper level of stratum 10, depending upon the thickness of the stratum. The invention has application to multiple strata separated by thin layers of shale or other non-producing strata.

Certain modifications of the invention will become apparent to those skilled in the art and the illustrative details disclosed are not to be construed as imposing unnecessary limitations on the invention.

We claim:

1. Apparatus for use in alternately injecting fluids into a stratum adjacent a well and producing fluids from said well comprising in combination:

(a) an elongated tube attachable at its upper end to a downhole tubing string below a pump thereon and open adjacent its lower end, said tube being unobstructed and open to flow from its upper end to the valve means of (b);

(b) valve means in a section of said tube at an intermediate level therein operable to allow ingress of uids directly from outside of said tube when in one position and to prevent egress of uids when in another position; and

(c) a tail pipe on the lower end of said tube communicating therewith for passing injected uids to a lower level in said well.

2. The apparatus of claim 1 wherein the tube of (a) is cylindrical and said tail pipe is arcuate, connecting'with said upper section intermediate the ends thereof thru an opening in the side thereof, said tail pipe extending downwardly to a point substantially below and approximately axially of the lower end of said upper section, and said valve means comprises a check valve in the lower end of said tube below said opening.

3. The apparatus of claim 2 wherein the lower end of said tail pipe terminates in a relatively short cylindrical section coaxial with said upper section.

4. The apparatus of claim 1 wherein said tube and tail pipe are cylindrical and coaxial and said valve means comprises ports in the wall of said tube and a cylindrical sleeve having matching ports, said sleeve `slidably engaging the inner wall of said tube, there being means on the upper end of said `sleeve for raising and lowering same within said tube to alternately align and disalign said ports.

'5. Apparatus in a well penetrating a relatively thick oil stratum comprising in combination:

(a) la tubing string extending from the wellhead into said stratum and including a pump seated in the lower end thereof;

(b) a rod string connecting with said pump extending -thru said tubing string and thru the wellhead;

(c) tan expanded section of tubing in said tubing string just above said pump for housing said pump during fluid injection into said stratum; 4and l(d) the apparatus of claim 1 extending from the lower end of said tubing string below said pump downwardly substantially to the bottom of said stra-tum.

6. The apparatus of claim 5 wherein said valve means is a check valve.

7. The apparatus of claim 5 wherein said valve means is a sleeve valve coaxial with said tubing string having ports therein, there being matching ports in the wall of said tube below said pump, said sleeve slidably engaging --the inner Wall of said tube and including means attached to the lower end of said pump for operating said sleeve into and out of matching position for said ports.

References Cited UNITED STATES PATENTS 2,374,922l 5/1945' IByrd 166-144 X 2,886,108 15/1959 Piety 166-110 X 3,273,644 9/1966 Waterman 166-105 X NILE C. BYERS, JR., Primary Examiner. 

